facebook bug has been found again.

today suddenly i think of to login in facebook with my changed email address and suddenly i saw that i can login with the old email address even it is removed from my account.

ok now straight on the bug producing steps:

1. login with your email and password
2. go to settings
   
3. click on in section (fig: 1)
4. then write new mail address and click
   
5. it will send you a email to the new email address
   
6. click on the verify link on just now added mail address.
   
7. remove old email address. (fig: 2)
   
8. now you also can login with your new & old email address.
   

fig: 1
fig: 2

it may be seems that it is not a bug but when user change his/her email, it means there is some problem with that email thats why user change that. so i think that is a security problem of facebook.